1. Field of the Disclosure
Aspects relate to position determination using multi-subscription selective diversity.
2. Description of the Related Art
Multi-Subscriber Identity Module (multi-SIM) wireless mobile devices have become increasingly popular because of the different costs associated with different services from different service providers. One type of multi-SIM wireless mobile device, a dual-SIM dual active (DSDA) device, allows simultaneous active connections with the networks corresponding to two SIMs. DSDA devices typically have separate transmit/receive chains associated with each SIM. Another type of multi-SIM wireless mobile device, a dual-SIM dual standby (DSDS) device, allows selective communication on a first network while listening for pages on a second network. Such a single receive (SR) configuration in a multi-SIM wireless mobile device is a very common implementation in low/value tier markets.
Position location determination and its accuracy is a growing challenge for wireless mobile devices. With more and more complex signal fading scenarios and the need to perform positioning operations in indoor environments, providing an accurate wireless mobile device position even when using the latest Long-Term Evolution (LTE) positioning protocol (LPP) remains an area of interest.
LPP supports Observed Time Difference of Arrival (OTDOA) as one of the mechanisms for position determination. This technique involves a wireless mobile device receiving assistance data (AD) from the network that assists the wireless mobile device to identify and measure positioning signals from multiple neighboring cells. The wireless mobile device can then estimate its own position based on the relative OTDOA of the positioning signals from the neighboring cells, or it can transmit the OTDOA measurements to the network to estimate the position of the wireless mobile device.
LPP thus involves multiple measurements of multiple neighboring cells, which is battery consuming, especially in IDLE mode, and affects the standby time of the wireless mobile device. This problem is even more severe for multi-SIM wireless mobile devices because the multiple subscriptions of the device will each perform these measurements. Another problem is that different subscriptions may provide different accuracy at different geographic locations based on that subscription's current serving cell, geometry of the available neighbors, synchronization, etc.